SECURITIES - Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Unrealized Loss Position For:
Estimated Fair Value	$ 65,789,907	$ 63,655,674
Gross unrealized losses	(4,963,091)	(673,774)
Agency Mortgage-Backed Securities
Unrealized Loss Position For:
Estimated Fair Value	34,321,645	23,211,971
Gross unrealized losses	$ (3,714,806)	$ (486,024)
Number of securities | security	2,610	590
Agency Mortgage-Backed Securities | Less than 12 months
Unrealized Loss Position For:
Estimated Fair Value	$ 33,061,267	$ 22,828,156
Gross unrealized losses	$ (3,448,120)	$ (475,064)
Number of securities | security	2,481	571
Agency Mortgage-Backed Securities | 12 Months or more
Unrealized Loss Position For:
Estimated Fair Value	$ 1,260,378	$ 383,815
Gross unrealized losses	$ (266,686)	$ (10,960)
Number of securities | security	129	19